mingw32-gcc: add gcc9 Xcode11 patch

[Gcenx]

Description

Currently i686-w64-mingw32-gcc-nothreads & x86_64-w64-mingw32-gcc-nothreads both fail to compile on macOS Catalina using Xcode11. (light also affects macOS Mojave as that also using Xcode11)

The patched was taken from gcc9 port that corrects the same issue.

Closes https://trac.macports.org/ticket/60091

Type(s)

• bugfix

Tested on

macOS 10.15.3 19D76
Xcode 11.3.1 11C504

Verification

Have you

• followed our Commit Message Guidelines?
• squashed and minimized your commits?
• checked that there aren't other open pull requests for the same change?
• referenced existing tickets on Trac with full URL?

• checked your Portfile with port lint?
• tried existing tests with sudo port test?
• tried a full install with sudo port -vst install?
• tested basic functionality of all binary files?

[macportsbot]

Notifying maintainers:
@mojca for port i686-w64-mingw32-gcc, x86_64-w64-mingw32-gcc.

[Gcenx]

This doesn't resolve the newer issue with i686-w64-mingw32-binutils & x86_64-w64-mingw32-binutils conflicting with the recent binutils version bump, I'll open an ticket for that later or pull-request to revert the change to both Portfiles

[macportsbot]

Travis Build #10520 Errored.

Lint results

--->  Verifying Portfile for i686-w64-mingw32-gcc
--->  0 errors and 0 warnings found.
--->  Verifying Portfile for x86_64-w64-mingw32-gcc
--->  0 errors and 0 warnings found.

Port i686-w64-mingw32-gcc-bootstrap success on xcode10.3. Log
Port i686-w64-mingw32-gcc-nothreads success on xcode10.3. Log
Port i686-w64-mingw32-gcc's dependencies fail on xcode10.3. Log
Port x86_64-w64-mingw32-gcc-bootstrap success on xcode10.3. Log
Port i686-w64-mingw32-gcc-bootstrap success on xcode9.4. Log
Port i686-w64-mingw32-gcc-nothreads success on xcode9.4. Log
Port i686-w64-mingw32-gcc's dependencies fail on xcode9.4. Log
Port x86_64-w64-mingw32-gcc-bootstrap success on xcode9.4. Log
Port i686-w64-mingw32-gcc-bootstrap success on xcode8.3. Log
Port i686-w64-mingw32-gcc-nothreads success on xcode8.3. Log
Port i686-w64-mingw32-gcc's dependencies fail on xcode8.3. Log
Port i686-w64-mingw32-gcc-bootstrap success on xcode7.3. Log
Port i686-w64-mingw32-gcc-nothreads success on xcode7.3. Log
Port i686-w64-mingw32-gcc's dependencies fail on xcode7.3. Log
Port x86_64-w64-mingw32-gcc-bootstrap success on xcode7.3. Log

The build timed out.

[Gcenx]

Going to go build everything again from source without this change, I'm starting to think the prebuilt packages are causing the stack issues,

[Gcenx]

Not required, the Portfile isn't an issue when building everything from source everything builds without issue.

Seems one of more of the prebuilt packages is causing the stack issue.